Synchronizing mechanism



Mach 31, 1936. A, D, ROBBINS 2,035,507

SYNCHRONI Z ING MECHANISM Filed July 26, 1934 2 Sheets-Sheet l If-'911 [EN ATTORNEYS March 31, 1936. A. D ROBB|N5 A2,035,507

SYNCHRONIZING MECHANISM Filed -uly 26, 1951; 2 SheetsSheet 2 f9.3 33 if V 37V 6x/ML;

' AT-roRNEY Patented Mar. 31, 1936 UNITED STATES'y PATENT j oFFlcE `2,035,50': srNcmtoNrzmG MEcnANrs'M Azor D. Robbins, New Brunswick, N. J., assignor to International Motor Company, New York, N. Y., a corporation of Delaware Application July zo, 1934, serial Natsaosi The present invention relates to transmission f mechanisms andembodies, more specically, an

I is provided and incorporated in the transmission in such fashion that the clutch mechanism synchronizes the speeds of rotation of two relativelyl rotating parts as the parts are moved into engaging position. It is to these forms ofsynchronizing mechanisms that the present invention relatesA and an object thereof is to provide a synchronizing device for transmissions wherein the design affords friction clutches of relatively large diameters, in l combination with friction cones from which the clutches are held free when the mechanismis not in action.

A further object of the invention is to provide a synchronizing device of the above character,

. 3,0 wherein the construction is such as to enable the shifter fork to be comparatively small in diameter, thus avoiding undesirable 'friction on the fork surface.

A further object of the `invention is to provide a device of the above character'whereln'the toothed clutches may be made comparatively small in diameter and are so formed as to vpre-v vent engagement thereof until they' have been' above, will be apparent as the invention is de-A f'scribe'd in greater detail in connection with the accompanying drawings, wherein:

f- Figure 1 is a longitudinal view in section, taken through the axis of a transmission mechanism having incorporated therein a synchronizing device constructed .in accordance with the present invention.

5 Claims. `(4f/1. 192-53) Figure 2 is a view in section, taken on line 2-2 of Figure 1, and looking in the direction of the arrows.

Figures 3 and 4 are similar to Figures 1 and 2, respectively, showing a modified form of the in- 5 vention, Figure 4 being taken on line 4-4 of Figure 3 and looking in the direction of the arrows, while Figure 3 is taken on the line 3-3 of Figure 4 and looking in the direction of the arrows. With reference to the above drawings, a 10 'driving 'shaft is shown at I0 upon which a driving pinion il may be f orm'ed, the shaft being journaled in. abearing I2 .in the transmission housing. A driven shaft I3 is centered and journaled by bearing I4 within the driving pinion 15 II and has a splined portion I5 formed thereon. Journaled upon the driven shaft is a driven gear 'I6 which is in constant mesh with a gear I1 secured to a countershaft I8.

a gear I9l which is in constant mesh with such pinionl and secured to the countershaft I8. Slidably mounted upon the splined section I5 is a clutch assembly 20. This clutch assembly is vprovided with a portion having clutch teeth 2I 25 which are'adapted to engage cooperating internal .clutchteeth 22 in the driving pinion II. The clutch assembly is also formed with a portion having clutch teeth 23 which are adapted to engage the internal clutch teeth 24, formed upon 30 the gear I6. A flange 25 is formed on the clutch assembly and provided with a grooved peripheral portion 26 within which a shifter fork 21 is adapted 'to engage.

Upon the clutch assembly 2li are journaled 35 collars 28 and 29 in'which strut bars 30are'supported. Upon the driving pinion II and gear IB, respectively, are secured clutch conesk 3l and 32, respectively, these cones ybeing' adapted to be engaged by synchronizing friction clutch mem- 40 bers 33 an(A 34, respectively, carried upon balk rings 33 and 34', respectively. The balk rings l33' and 34' are formed with central openings 35 within which the toothed clutch members 2| and 23 are received. The openings 35 are formed 45 with flat surfaces 36 and the `toothed clutch members 2| and 23 are formed with spaced flat portions 31 to cooperate with the flat surfaces 36 and thus prevent relative rotation of rings 33' 50 and 34 with respect to' the clutch members 2I and 23. Y

The balk rings 33 and 34' are secured to the ends of the strut bars 30 and this assembly is centered by means oi? balls 38 which are urged 55 `The counterf .shaft is driven from the driving pinion I I through 2o l'to c tive speeds of rotation differ. of rotation of the gear Il and clutch assembly 20 into recesses 39, formed in the strut bars by means of springs 40. The flange 25 of the clutch assembly 20 is formed with elongated openings 4| through which the strut bars 30 pass, the assembly of the synchronizing clutch members, strut bars and collars beingeffected by forming the collars 28 and 29 in halves in order that they maybe assembled on the clutch assembly 20. As shown in the sectional View of Figure 1, the balls 38 and springs 40 are received in recesses 42, formed in the ange 25 and the mechanism is thus readily assembled and functions effectively to maintain the synchronizing clutches in a centered position.

`When it is desired to engage the driving pinion the clutch assembly 2|) is moved to the left, as viewed in Figure 1 by means of the fork 21. 'Ihe balls 38 carry the strut bars and synchronizing fr'iction clutch member 34 in the same direction, thus frictionally engaging the clutch member 33 with the conev 3l. If the driving pinion is rotating faster than the clutch member 33, the latter will tend to turn in the same direction as the pinion due to the friction existing between the cone 3| and the clutch member 33. Inasmuch as the clutch member 33 cannot turn on the teeth 2|, the speed of the clutch teeth 2| is synchronized with respect to the speed of teeth 22.

By reason of the, angular plane which the surffaces 36 and 31 present to the direction of force applied to the clutch, these surfaces will engage with a relatively high pressure and thereby frictionally resistA axial movement of the sliding clutch assembly.l 'I'his resistance of the flat surfaces assists the springs and balls 38 in carrying the clutch member 33 into engagement vwith the cone 3|. In this fashion, though considerable force may be applied to the shifting fork 21, the clutch teeth 2| cannot be clashed with the clutch teeth 22 of the -driving pinion while their rela- When the speed are the same, the pressure on the flat surfaces 36' andf'31 is relieved inasmuch as only'the resistance of springs 40 must be overcome. In this fashion, the teeth 2| and 22 may be easily engaged.

In the construction shown in Figures 3 and 4, the assembly consists of elements united by simple welding operations. The spline shaft and associated gear construction is similar to the corresponding elements of the form of the invention shown in Figures 1 and 2 Aand therefore will not be described again. The clutch assembly, however, is formed of a plurality of elements including a clutch member having clutch teeth 5| which are adapted to engage teeth 22 Yand teeth l2 which are adapted to enga'g'ejeeth 24. The teeth Il and 52 .are cut away' at three equidistantly spaced'points around the peripheries thereof as shown at 534m Figure 4, bosses 54 being formed atthe bottoms of the cut-away portions and adapted to cooperate with balk ring ties 55, the ends of which are welded to balk rings 56 and 51- which are formed with the friction members 33 and 34, respectively. The balk ring ties are .formed with feet 58 which are'adapted to engage the bosses 54 upon relative rotation of the rings -with respect tothe clutch mhiherjl,

the angle of contact between these members being such as to produce considerable'frictional .resistance to relative anal motion therebetween, as described in connection with the constructionV 75showninFlglnes1and2. Y

The clutch member 50 is formed with an intermediate circumferential groove 59 Within which a two piece collar 60 isadapted to be secured. As shown in Figures 3 and 4, each piece of the collar is secured to the clutch hub by means of tw o screws 6|. The collar is formed with a recess 62 Within which a centering spring 63 is received, this centering spring engaging notches 66' in the balk ring ties 55 to center the clutch with respect to the clutch members 22 and 24.

The resulting structure will be seen to be simple' The shifter fork is relatively A While the invention has been described with specific reference to the accompanying drawings, it is not to be limited, save as dened in the appended claims.

I claim as my invention:

1. A transmission mechanism having relatively rotatable members, one-of which is slidable axially of the other, cooperating teeth on the members adapted to be engaged upon relative axial movement between the members, a plate secured to one of the members an'd formed with a friction surface adjacent its periphery, a second plate slidably but non-rotatably mounted fupon the slidable member, the second plate and slidable member being formed with cooperating at surfaces lying in angular planes with respect to the direction of force transmitted therebetween and spaced from the axis of the members, whereby relative rotation between the second plate and the slidable member causes engagement of the flat surfaces to produce a jamming action regardless of the relative axial positionof the members, and a friction surface adjacent the periphery of the second plate adapted to vcooperate with the first friction surface.

2. A transmiion mechanism having relatively rotatable members, one of which is slidable axially of the other, cooperating teeth on the members adapted to be engaged .upon relative axial movement between the members, a plate secured to one of the members and formed with a friction surface adjacent its periphery, a second plate 'slidably but non-rotatably mounted upon the slidable member, a friction surface adjacent the periphery of the second plate adapted to cooperate with the rst friction surface, supporting rods slidably mounted on the slidable member and mounting the second plate, the slidable member being formed with elongated slots to receive the rods, the rods being slidably mounted in collars journaled on the slidable member, and yielding means to maintain the rods in a normal position.

3. A transmission mechanism having an axially fixed gear and a coaxially slidable clutch -member, the gear and clutch member having cooperating clutch teeth, a plate secured to the xed gear and formed with a conical friction surface, a second plate having a cooperating fricl tion surface, means to mount the second plate the rods.

slidably but non-rotatably on the clutch member, a peripheral flangel on the clutch member adapted to be engaged by shifter elongated slots in the flange, supporting rods in the slots,

collars on opposite sides of the flange formedv with apertures in which the rods are slidable axially, and means to/aiount the second plate on 4, s transmission meenemen naman 'sx1- ally fixed gear and a coaxially slidable clutch member, the gear and clutch member having cooperating clutch teeth, a platesecured to the fixed gear and formed with a friction surface, a second plate having a cooperating friction surface, meansito mount the second 'plate sudably but lnon-'rotatably on the clutch member, a peripheral flange on the clutch member adapted to be engaged by shifter mechanism, elongated slots in the flange, supporting rods in the slots, collars on opposite sides of thef'iange formed with apertures in which the rods are slidahle axially, Yielding means to center the rods on the flange, and

means to mount the second plate on the rods.

A' transmission m havingA a gear.

a coaxially sliclable clutch member, f

clutch'teeth on' the gear and clutch member whereby the last named member may be-moved axially to engagez. the gear, a plate secured to the gear and formed with a friction surface, a

second plate having a cooperating friction sur-- face, means to mount. the second plate slidably but non-rotatably on the' clutch member, the second plate and clutch member being formed with cooperating lying in angular planes with respect to the direction of force transmitted therebetween and spaced from the axis of the members, whereby relative rotation between the Isecond plate and the slidable mem-l ber causes engagement of the fiat surfaces to produce a Jamming action regardless of the relative axial position of the members, a peripheral 

